Just read through the posts on your barn. I'm not trying to alarm you, but just want to mention a couple of things.
As RoS said earlier, I'm an electrician, and the first thing I would do is kill the circuit (which I see you've done). Get someone knowledgable about electrical stuff to check the circuit and find the problem. It could be a loose connection, or a rodent chewing through the cable (they sharpen their teeth on the metal).
Another thing to check is for the smell of smoke, or anything that's warm that shouldn't be. (I'm also a volunteer fireman). I once got a call to a house that had been burning (smoldering) for three days before anyone noticed.
Thank you deaconjim.... I have killed that circuit at the breaker. My little hand-held circuit tester gets NOTHING at all anywhere in that line. I'll be having someone out there but not till payday if it isn't an emergency.
If I smelled any kind of electrical or smoke smell, I wouldn't have the horses in there. Very fearful of such things and it's a great concern.